In a bowl, combine the peeled shrimp, Cajun seasoning, olive oil, lime juice, salt, and pepper. Toss to coat the shrimp evenly in the spice mixture.
Heat a non-stick skillet over medium-high heat. Once hot, add the seasoned shrimp and cook for 2-3 minutes on each side, or until they are pink and opaque. Remove from heat.
While the shrimp are cooking, warm the corn tortillas in another skillet over low heat, about 30 seconds on each side.
Assemble the tacos by placing a few pieces of cooked shrimp on each tortilla.
Top the shrimp with sliced avocado, shredded red cabbage, and chopped cilantro.
In a small bowl, mix together sour cream and lime zest. Drizzle this creamy mixture over the assembled tacos.
Serve immediately, with lime wedges on the side for squeezing over the tacos.